A method is known in the art in which metal bumps are formed on pads of a semiconductor chip by applying electroless plating or the like. The semiconductor chip is electrically connected to an interconnect pattern (leads) on a substrate by allowing solder applied to the metal bumps to melt, for example. According to this method, the pads can be connected to the leads by melting the solder, differing from the case of connecting the pads to the leads by applying heat and pressure to the leads, thereby decreasing the amount of pressure applied to the surface of the semiconductor chip. This allows the pads to be disposed not only in the end sections of the semiconductor chip but also in a device formation region, whereby a larger number of pads can be disposed at a coarser pitch. Moreover, use of solder ensures that a semiconductor device can be fabricated at low cost in comparison with the case of forming gold bumps.
However, according to this configuration, solder applied to each pad may flow onto the adjacent pads upon melting when connecting the pads to the interconnect pattern, thereby causing a short circuit to occur between the pads. This problem cannot be solved by merely decreasing the amount of solder applied to each pad.